The potential reasons for PPAR‐γ functioning across a wide range of cell types are as follows: (1) thiazolidinediones could act upstream insulin resistance, including ingestive behaviour, adiposity and inflammation; (2) insulin resistance has organ‐specific effects that abrogate PPAR‐γ expression in different cell types;23, 24, 25 and (3) the transgenic mouse lines expressing PPAR‐γ with cell‐type‐specific promoters may still generate unwanted transgene expression in other cell types. The gene discussed is PPARG; the disease is Insulin resistance.